A curable resin composition may be applied on a substrate to form a paint film and used to form a pattern by subjecting a specific portion of the paint film to exposure by light irradiation using a photomask and the like and then subjecting a non-exposure portion to a development treatment to remove the non-exposure portion. This curable resin composition has been used for a photocurable ink, a photosensitive printing plate, various photoresists, a color filter photoresist for a LCD, a photoresist for a resin black matrix, a transparent photosensitive material or the like since the curable resin composition may be polymerized and cured by light irradiation.
The curable resin composition usually includes an alkali soluble resin, a polymerizable compound including an ethylenically unsaturated bond, a photopolymerization initiator and a solvent.
In the curable resin composition, an alkali soluble resin allows the curable resin composition to have adhesive strength with a substrate and thus a coating may be formed, is dissolved in an alkali liquid developer to allow a fine pattern to be formed, and simultaneously serves to prevent an obtained pattern from being broken during a post-treatment process by imparting strength to the pattern. Further, the alkali soluble resin has great effects even on heat resistance and chemical resistance.
In general, the curable resin composition is formed as a coating film having a thickness of 3 μm or more and most of the coating film needs to be developed, and thus the curable resin composition needs to be dissolved in a large amount in a liquid developer within a short time period. In addition, when development is not clearly performed, various display defects such as direct spots due to residues and alignment defects of liquid crystals may occur. Therefore, the curable resin composition needs to have excellent developability. Moreover, when a curable resin composition is applied on a glass substrate with a large surface area, it is difficult for the substrate to be subjected to full-surface exposure, and thus the substrate is subjected to exposure in multiple sequences. Thus, when the curable resin composition has low sensitivity, the time needed for the exposure process becomes longer, resulting in a drop in productivity, and thus high sensitivity is required.
Moreover, even in a high temperature process at 200° C. or higher, excellent thermal stability for maintaining the shape and thickness, high compress strength sufficient to resist against external pressure and excellent chemical resistance are required. In addition, excellent stability with time may stably exhibit characteristics which are constantly required without any changes even under long-term storage conditions, and thus excellent stability with time is required. However, a curable resin composition that meets all the standards in terms of heat resistance, chemical resistance, developability, sensitivity and stability with time has not been yet developed.
Furthermore, in a process of using the above-described curable resin composition, in order to improve a yield per unit time of the process, exposure time and development time are reduced. Thus, there is a need for improving sensitivity and developability, compared to curable resin compositions that are known in the art.
Meanwhile, in a curable composition such as the curable resin composition, there are fundamental problems such as inability to improve resolution intrinsically in a pigment distribution system in the art, occurrence of color spots due to coarse particles of a pigment and the like, and thus the use of a dye has been required. However, a curable composition containing a dye is problematic in that various performances such as light resistance, heat resistance, solubility, coating uniformity and the like are poor, compared to a curable composition in which a pigment is used.
Therefore, there is a need for studies on a curable composition including a dye having excellent light resistance, heat resistance, solubility, coating uniformity and the like.